Where is "Override Parent Ranges"?

Hi, I have introduced a new second keyboard into my MainStage setup.

I've created a channel strip at the concert level with a software instrument. So far so good, plays the same sound on the second keyboard no matter what patch I select. That is what I want. However, I'd like to be able to override that on certain patches and have the keyboard trigger a different channel strip.

This document seems to tell me how to do that - https://support.apple.com/kb/PH13575?locale=en_CA, but I get stalled at "In the “Override parent ranges” pop-up menu". I've tried selecting all the channel strips in this patch, and cannot seem to see this pop up menu anywhere.

Does anyone know where I should look for that?